{"id":6808,"date":"2021-03-01T00:05:00","date_gmt":"2021-03-01T05:05:00","guid":{"rendered":"http:\/\/www.dontow.com\/?p=6808"},"modified":"2021-03-01T00:15:23","modified_gmt":"2021-03-01T05:15:23","slug":"quantum-physics-and-quantum-computing","status":"publish","type":"post","link":"http:\/\/www.dontow.com\/2021\/03\/quantum-physics-and-quantum-computing\/","title":{"rendered":"Quantum Physics and Quantum Computers"},"content":{"rendered":"\n
In two recent articles in this website, we discuss Quantum Physics (QP), the remarkable scientific discovery of the 20th century that has revolutionized science as well as all aspects of our civilian and military lives. <\/p>\n\n\n\n
The first article [1] discussed several mysteries of QP, notably, particle-wave duality, uncertainty principle, probabilistic interpretation of experiments, act of measurement can change what you are observing, and the superposition principle<\/span>. <\/p>\n\n\n\n The second article [2] discussed what Einstein called “spooky action at a distance,” experimental verification of QP versus deterministic predictions of local hidden variable theories a la Bell’s Theorem, and quantum<\/span> entanglement<\/span>.<\/p>\n\n\n\n The current article discusses how Quantum Physics’ superposition principle and the concept of entanglement can lead to major breakthroughs for computer processing power and computer security.<\/p>\n\n\n <\/p>\n\n\n First we briefly review some of the basics of computers. All information in computers are represented by bits of data. A bit of data can be represented by a 0 or 1, or on or off in terms of an electrical circuit or switch. When we process data in a computer, we are processing a stream of electrical or optical pulses representing 0s and 1s. For example, if we are describing the result of a coin flip, the result is either head (1) or tail (0). So we can represent coin flip with a wire with either electricity or no electricity flowing through it. With transistors, the transistor is turned on when the amount of electricity flowing through the wire connected to the transistor is above a certain threshold, and is turned off when the electricity is less than that threshold. Thus, the coin flip can be described with a single wire connected to a transistor.<\/p>\n\n\n\n What about a more complex situation than describing a coin flip, such as describing which of 3 light bulbs is turned on. Then you need more bits, or more wires, each connected to a transistor, and in this case of 3 light bulbs, you need 3 wires. Thus we see that we can describe more complex physical phenomena by using more and more bits, or more and more wires and transistors. <\/p>\n\n\n\n If we combine 8 bits of data in what is called a byte, which has 28<\/sup> or 64 combinations. Then a byte can represent the English alphabet. Therefore, information about our world can be represented by combining more bits and bytes together. That is why we hear of terms like kilobytes (a thousand bytes), megabytes (a million bytes), gigabytes (a billion bytes), terabytes (a trillion bytes), petabytes (1,000 terabytes). [3] Bigger and faster computers can simultaneously handle larger and larger number of bytes.<\/p>\n\n\n\n A 200-page book with about 300 words per page has about 60,000 words. A word on the average has about 6 characters. This means that a 200-page book has about 360,000 characters. If we use one byte to represent each character, then this book would have about 360 kilobytes of data.<\/p>\n\n\n\n A newer and better computer usually can process more data and process the data faster than the previous generation of computers. So newer computers will normally have larger or more compact and faster processors and with creative designs in algorithms and software to get additional processing power.<\/p>\n\n\n\n With quantum computers, there is a novel way of increasing the processing power and speed without adding more bits which are manifested by adding more circuits and transistors. Instead of using streams of electrical or optical pulses representing 1s or 0s associated with bits, quantum computers use subatomic particles such as electrons or photons and the quantum physics concept of the superposition of states so that a quantum physical system is a superposition of many states. [3] And the system does not collapse to a single state until there is a measurement. The quantum physical system is called a quantum bit or Qubit. So if the quantum physical system is a superposition of n states, then there are n possible 1s or 0s. This means that using a quantum system instead of a traditional system, the number of bits has just been increased by a factor of n.<\/p>\n\n\n\n It is not easy to create these quantum physical systems. Generating and managing Qubits is a great scientific and engineering challenge. Currently only a small number of companies and university research labs (such as IBM, Google, Rigetti Computing in Berkeley, and IonQ in College Park) have constructed quantum computers. They use superconducting circuits cooled to temperatures colder than deep space, or trap individual atoms in electromagnetic fields on a silicon chip in ultra-high-vacuum chambers. In both cases, the goal is to isolate the Qubits in a controlled quantum state. To put Qubits into superposition, researchers manipulate them using precision lasers or microwave beams. We are currently at the beginning of the age of quantum computers. That is why most current quantum computers have only a few dozen Qubits, although IBM has announced that they will build a a quantum computer with 1,000 Qubits by 2023. [4]<\/p>\n\n\n\nBrief Review of Computer Bits and Their Physical Implementation:<\/span><\/strong><\/h4>\n\n\n\n
From Bits to Qubits and the Superposition Principle<\/span><\/strong>:<\/h4>\n\n\n\n